SD12C - 12V Bidirectional TVS Diode ESD Protection | Semtech
N.º de pieza: SD12C ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0.95 | $0,95 |
| 10 | $0.86 | $8,60 |
| 100 | $0.72 | $72,00 |
| 500 | $0.61 | $305,00 |
| 1.000 | $0.52 | $520,00 |
| 3.000 | $0.44 | $1.320,00 |
SD12C Descripción general
A TVS diode is a semiconductor protection device that clamps transient overvoltages to a safe level by avalanching when the voltage across it exceeds its breakdown threshold. TVS diodes belong to the broader category of circuit protection devices, sitting alongside varistors (MOVs), fuses, and polymer PTC resettable fuses within the electromagnetic compatibility (EMC) protection hierarchy. They are essential for any external connector, button, or data line exposed to ESD, cable discharge event (CDE), electrical fast transient (EFT), or induced lightning surge energy.
Key features of the SD12C include a 12 V working voltage (Vrwm) suitable for protecting Vbus and signal lines up to 12 V, a low clamping factor that limits stress on downstream components, a sub-nanosecond response time, and a typical leakage current below 1 µA at the working voltage. The SOD-323 (SC-76) package occupies only 1.6 mm × 1.35 mm of PCB area, enabling ultra-dense layouts in smartphones, wearables, and USB-C connectors.
Technically, the SD12C uses a silicon PN-junction structure engineered for repetitive surge endurance and stable clamping across temperature. The bidirectional configuration eliminates orientation errors during assembly and protects against both positive and negative transients on a single line, which is critical for AC-coupled signal lines such as audio, USB D+/D-, or analog sensor outputs.
Typical applications include ESD protection for USB 2.0/3.0 data lines, smartphone audio jacks, HDMI/MHL interfaces, button/switch contacts, battery management system (BMS) communication lines, and portable medical device user interfaces. Designers select the SD12C for its small footprint, low capacitance, and proven reliability in high-volume consumer electronics.
When designing with the SD12C, place the device as close as physically possible to the connector or entry pad to minimize the loop area for ESD current. Use a ground via directly beneath the SOD-323 thermal/ground pad to provide the lowest-inductance discharge path. Verify that the protected signal's maximum normal operating voltage remains below the 12 V Vrwm rating to avoid continuous conduction and leakage heating.
This page synthesizes distributor pricing, drop-in alternatives, application circuit examples, and practical PCB layout design guidance not aggregated on the manufacturer datasheet, giving design engineers a single, decision-ready reference.
Alternativas directas para SD12C — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con SD12C (mismo factor de forma y huella) — difiere en Operating Temperature.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
SD12C.TCT
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
SD12C-01FTG
✅ Sustitución directa✓ En stock
$0.11 / unidad
Ver hoja de datos →SD12C
✅ Sustitución directa✓ En stock
$0.44 / unidad
Ver hoja de datos →SE3D35B12A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
SD12C
✅ Sustitución directa✓ En stock
$0.44 / unidad
Ver hoja de datos →SD12C Valores máximos y características eléctricas
| Manufacturer | Semtech Corporation |
| Device Type | Bidirectional TVS Diode (Single Line) |
| Working Voltage (Vrwm) | 12 V |
| Clamping Voltage (Vc) | 24 V at 15 A (8/20 µs) per Semtech listing; 24 V at 24 A per SMC Diode listing |
| Peak Pulse Current (Ipp) | 15 A (8/20 µs, Semtech) / 24 A (8/20 µs, SMC Diode) |
| ESD Rating (Air Discharge) | ±15 kV per IEC 61000-4-2 |
| ESD Rating (Contact Discharge) | ±8 kV per IEC 61000-4-2 |
| Leakage Current | <1 µA at Vrwm (typical) |
| Response Time | <1 ns |
| Encapsulado | SOD-323 (SC-76) |
| Tipo de montaje | Surface Mount |
| Temperatura de funcionamiento | -55 °C to +125 °C (typical TVS industrial range) |
| Configuration | Bidirectional (single line) |
| Polarity | Bidirectional |
| Estado RoHS | Compliant |
| Nivel MSL | 1 (per JEDEC J-STD-020, typical for SOD-323 TVS) |
Configuración de pines de SD12C
| Pin 1 | Line — Bidirectional protected line connection (no polarity) |
| Pin 2 | Line — Bidirectional protected line connection (no polarity, electrically equivalent to pin 1) |
Aplicaciones típicas
SD12C es adecuado para 7 aplicacións: USB 2.0 / USB-C Data Line ESD Protection, Smartphone Audio Jack Protection, HDMI / DisplayPort Interface Protection, Button and Keypad Contact ESD Protection, Portable Medical Device User Interface Protection, Battery Management System (BMS) Communication Lines, Industrial Sensor I/O Protection.
USB 2.0 / USB-C Data Line ESD Protection
The SD12C protects USB 2.0 D+ and D- data lines from ESD strikes during cable insertion and user contact, which can otherwise latch-up or destroy the USB transceiver PHY. Its 12 V working voltage comfortably exceeds the USB Vbus maximum of 5 V while its sub-nanosecond response clamps the transient before it reaches the transceiver. Per IEC 61000-4-2, the SD12C's ±15 kV air / ±8 kV contact rating covers Level 4 ESD events typical of consumer port testing. Place one SD12C on each D+ and D- line, as close to the connector as physically possible, with the ground pad tied through short, direct vias to the chassis ground plane. This arrangement provides repeatable ESD suppression without degrading the 480 Mbps high-speed signal because of the device's low capacitance.
Recomendado
Smartphone Audio Jack Protection
The 3.5 mm audio jack on a smartphone is one of the most ESD-exposed mechanical interfaces, subject to direct skin contact, cable discharge events, and induced surge from nearby cellular transmitters. The SD12C, placed across the audio left/right signal path and ground, clamps cable discharge events (CDE) that occur when a charged headset is plugged in, limiting stress on the codec's line amplifier. Its bidirectional configuration eliminates orientation errors during PCB assembly, which is critical on high-volume consumer production lines. The SD12C's 12 V working voltage is well above typical 2 Vrms audio signal swings, so leakage at idle remains negligible and does not affect noise floor or THD+N. The SOD-323 footprint fits comfortably in the dense analog section of a smartphone mainboard.
Recomendado
HDMI / DisplayPort Interface Protection
HDMI and DisplayPort connectors carry high-speed TMDS/aux signals alongside a 5 V supply and hot-plug detect line, all of which are vulnerable to ESD during cable insertion and removal. The SD12C, placed on each data line and the 5 V supply return, clamps ESD and CDE events before they reach the HDMI receiver. Its 12 V Vrwm easily covers the 5 V supply transients seen during hot-plug, while the low capacitance preserves signal integrity on multi-Gbps TMDS lanes. Per HDMI compliance test ID 7-9 (ESD), the SD12C's ±15 kV air discharge rating meets consumer HDMI compliance requirements. Use one device per signal line and place them within 5 mm of the HDMI receptacle.
Recomendado
Button and Keypad Contact ESD Protection
Mechanical buttons, keypads, and rotary encoder inputs are physically exposed user interfaces that frequently receive direct finger ESD discharges. The SD12C, placed between each switch contact and the MCU GPIO input, shunts ESD current to ground before it reaches the controller's ESD diodes, which often have limited current-handling capability. The 12 V working voltage is far above typical 3.3 V GPIO logic levels, so the SD12C does not interfere with normal button reads and adds no measurable leakage to the pull-up network. Its sub-nanosecond response prevents MCU latch-up that can occur when slow-clamping varistors allow voltage overshoot above the GPIO's absolute maximum. The compact SOD-323 package fits directly behind each button pad on the PCB.
Recomendado
Portable Medical Device User Interface Protection
Portable medical electronics such as glucose meters, pulse oximeters, and wearable health monitors must meet IEC 60601-1-2 EMC requirements, including ±15 kV air and ±8 kV contact ESD on every user-accessible surface. The SD12C, placed on each user-input pin and the enclosure ground return, provides the clamping required for medical EMC compliance while its bidirectional operation handles both positive and negative ESD events. The 12 V working voltage is appropriate for typical 3.3 V or 5 V analog front-end rails used in biosignal monitoring, and the low leakage (sub-µA) preserves the accuracy of low-current measurement channels. Per the Semtech SDxx family datasheet, the SD12C's IEC 61000-4-2 Level 4 rating helps medical OEMs pass pre-compliance testing faster.
Recomendado
Battery Management System (BMS) Communication Lines
Battery packs for power tools, e-bikes, and handheld industrial equipment expose SMBus or proprietary communication lines to ESD when the pack is removed or inserted. The SD12C, placed across each SMBus line and ground, clamps ESD events during hot-swap and protects the fuel gauge and battery monitor IC from damage. Its 12 V working voltage comfortably exceeds the typical 4.2 V maximum cell voltage plus headroom for transient ringing during switching. The bidirectional configuration protects both clock and data lines without orientation mistakes during assembly, and the SOD-323 footprint fits in the dense battery management PCB area. For multi-cell packs up to 12 V nominal, the SD12C's Vrwm rating provides adequate margin against the maximum bus voltage.
Recomendado
Industrial Sensor I/O Protection
Industrial 4-20 mA loops, RS-485 transceivers, and analog sensor outputs are often run to remote connectors in electrically noisy environments where induced surge from motor switching or lightning is common. The SD12C, placed at the connector entry of each sensor line, clamps surge energy and prevents propagation into sensitive analog front-ends. Its 12 V working voltage is appropriate for 5 V or 10 V analog signal rails, while the bidirectional configuration handles differential-mode surge on RS-485 A/B lines. Per Semtech application guidance, the SD12C's 350 W peak pulse rating on the 8/20 µs waveform provides adequate margin against induced surge from nearby switching events on the factory floor.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para SD12C — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | SD12C.TCT | SD12C-01FTG | SD12C (SMC Diode) | SE3D35B12A | SD12C (Diodes Inc) |
|---|---|---|---|---|---|---|
| Package | SOD-323 | SOD-323 - same | SOD-323 - same | SOD-323 - same | SOD-323 - same | SOD-323 - same |
| Brand | Semtech | Semtech | Littelfuse | SMC Diode Solutions | Semiware | Diodes Incorporated |
| Working Voltage (Vrwm) | 12 V | 12 V | 12 V | 12 V | 12 V | 12 V |
| Configuration | Bidirectional | Bidirectional | Bidirectional | Bidirectional | Bidirectional | Bidirectional |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
Diferenciadores clave
- Largest in-stock distributor footprint with same-day shipping (frente a SD12C-01FTG (Littelfuse))
- Original Semtech brand with established MLV-replacement pedigree (frente a SMC Diode Solutions SD12C and Diodes Incorporated SD12C)
- Bidirectional single-line configuration eliminates PCB orientation errors (frente a Unidirectional TVS diodes in SOD-123 or similar packages)
Notas de diseño
Place the SD12C within 3 mm of the protected connector pad or entry via, and route the protected trace directly through the device with no stubs or branches. The ground pad beneath the SOD-323 package must be tied to the chassis ground plane through at least two direct, short vias placed immediately under the device. This minimizes the high-frequency loop area seen by ESD current and prevents the trace inductance from generating a secondary overvoltage that can defeat the TVS clamp. Per Semtech application guidance, every additional millimeter of trace between connector and TVS degrades ESD performance measurably.
Do not select a TVS with Vrwm below the maximum normal operating voltage of the protected line. If the protected signal can exceed 12 V under normal conditions (e.g., 12 V Vbus with ringing, inductive load transients), the SD12C will conduct continuously and dissipate thermal energy, potentially failing. Verify the maximum steady-state and transient operating voltage, then add at least 10% headroom below the SD12C's 12 V Vrwm. For 5 V logic or USB data lines, the SD12C provides ample margin.
Keep the SD12C away from sensitive analog signal traces and avoid routing protected and unprotected traces in parallel for long distances - this creates capacitive coupling that can bypass the TVS. Use a ground guard trace or ground pour between the protected side and the rest of the circuit. For multi-line protection (USB D+/D-, HDMI TMDS), use one SD12C per line and place them symmetrically so each line sees the same ESD loop inductance. Add a bulk 0.1 µF ceramic capacitor on each protected supply rail near the TVS to filter residual post-clamp ringing.
Información de cumplimiento
RoHS compliant and lead-free per Semtech product page and Diodes Incorporated cross-listing. SOD-323 termination uses matte-tin plating, qualified to MSL 1 per JEDEC J-STD-020. No SVHC declarations above the 0.1% REACH threshold. AEC-Q100 not applicable - this is a generic portable-consumer TVS; for automotive-grade requirements consider AEC-Q100-qualified variants from other vendors.
